I think in some (maybe many) cases it is a "pissing contest." In other, and probably the majority, of cases I'd hope it is a case of simple inexperience coupled with arrogance resulting from the relative immaturity of the field. And I mean "immaturity" in more than one sense. The industry itself is young, especially compared to "traditional" engineering and sciences, and it is also filled with a high proportion of relatively immature people, at least in comparison to the slice of academia I was in.